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1.
Sensors (Basel) ; 24(3)2024 Jan 28.
Artículo en Inglés | MEDLINE | ID: mdl-38339566

RESUMEN

In recent years, the problem of cyber-physical systems' remote state estimations under eavesdropping attacks have been a source of concern. Aiming at the existence of eavesdroppers in multi-system CPSs, the optimal attack energy allocation problem based on a SINR (signal-to-noise ratio) remote state estimation is studied. Assume that there are N sensors, and these sensors use a shared wireless communication channel to send their state measurements to the remote estimator. Due to the limited power, eavesdroppers can only attack M channels out of N channels at most. Our goal is to use the Markov decision processes (MDP) method to maximize the eavesdropper's state estimation error, so as to determine the eavesdropper's optimal attack allocation. We propose a backward induction algorithm which uses MDP to obtain the optimal attack energy allocation strategy. Compared with the traditional induction algorithm, this algorithm has lower computational cost. Finally, the numerical simulation results verify the correctness of the theoretical analysis.

2.
IEEE Trans Cybern ; 51(2): 779-788, 2021 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-31545762

RESUMEN

In this article, we investigate optimal transmission power allocation at a sensor equipped with the energy-harvesting technology for remote state estimation in wireless cyber-physical systems. The sensor has access to an energy harvester, which can collect energy from the external environment and is an everlasting but unreliable energy source compared with conventional batteries. For the wireless dropping communication channel, the packet dropout rates depend on both the signal-to-noise ratio and the transmission power used by the sensor. We formulate the problem of the optimal transmission power allocation to minimize the remote estimation error covariances as a Markov decision processes (MDPs) subject to energy constraint of the sensor. By analyzing the MDP algorithm, we show that an optimal deterministic and stationary transmission power policy exists. Moreover, we show that the optimal policy has a threshold-type structure. A numerical simulation is provided to illustrate the performance of the transmission power allocation algorithm.

3.
Langmuir ; 34(36): 10748-10756, 2018 09 11.
Artículo en Inglés | MEDLINE | ID: mdl-30148369

RESUMEN

Tannic acid (TA) is a natural polyphenol compound with a broad spectrum of biological activities, the most notable of which being antioxidation. Poloxamer 188 (P188), a synthetic triblock copolymer of poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide), is amphiphilic in nature and best known for its ability to seal structurally damaged cellular membranes. The integration of both substances onto planar substrates could bring a new option for multifunctional coatings that are advantageous for implantable biomedical devices. Here, we demonstrate the feasibility of multilayer assembly of TA/P188 toward such a coating based on hydrogen bonding between phenolic hydroxyls of TA and ether groups of P188, and the unique surface feature it generates. The interactions between these two compounds were studied both in solution and in substrate-supported layer-by-layer assembly. The multilayer assembly process exhibits an exponential growth pattern as characterized by UV-vis spectrophotometry and quartz crystal microbalance with dissipation. Morphologically unique, microdome-shaped surface features emerge and evolve with the number of layers assembled. Such features bring a reservoir function to this coating, as demonstrated by the loading of hydrophobic nile red dye. Furthermore, the presence of TA in the multilayers was revealed by silver nitrate staining, and its antioxidation activity was demonstrated through a 2,2-diphenyl-1-picryl-hydrazyl free-radical scavenging assay.

4.
J Org Chem ; 82(8): 4317-4327, 2017 04 21.
Artículo en Inglés | MEDLINE | ID: mdl-28351150

RESUMEN

A novel one-pot 1,3-dipolar cycloaddition of indolenines, 3-aminooxindoles, and aldehydes is reported. The reaction provides indolenine-substituted spiro[pyrrolidin-2,3'-oxindoles] containing four contiguous stereogenic centers in high yields (up to 99%) and excellent diastereoselectivities (up to >20:1 dr) under mild conditions. Remarkably, the inversion of diastereoselectivity could be readily achieved through slightly modifying the reaction conditions.

5.
Diagn Microbiol Infect Dis ; 85(1): 61-5, 2016 May.
Artículo en Inglés | MEDLINE | ID: mdl-26976720

RESUMEN

We report a case of mycotic keratitis caused by Bipolaris oryzae with predisposing trauma from a foreign body. The fungus was identified by sequencing the internal transcribed spacer region, translation elongation factor 1α (TEF1) gene, and partial glyceraldehyde-3-phosphate dehydrogenase (GPDH) gene, and the species identity was confirmed on the basis of its characteristic conidial phenotype. The patient was treated with surgical intervention and antifungal agents, including intravenous fluconazole (FLC), oral itraconazole, topical 0.15% amphotericin B eye drops, and 0.5% FLC eye drops. To our knowledge, this is the first report of mycotic keratitis caused by B. oryzae worldwide.


Asunto(s)
Ascomicetos , Queratitis/diagnóstico , Queratitis/microbiología , Infecciones Oportunistas/diagnóstico , Infecciones Oportunistas/microbiología , Anfotericina B/administración & dosificación , Anfotericina B/uso terapéutico , Antifúngicos/administración & dosificación , Antifúngicos/uso terapéutico , Ascomicetos/clasificación , Ascomicetos/citología , Ascomicetos/genética , Ascomicetos/ultraestructura , Genes Fúngicos , Humanos , Queratitis/tratamiento farmacológico , Masculino , Persona de Mediana Edad , Soluciones Oftálmicas , Infecciones Oportunistas/tratamiento farmacológico , Filogenia , Resultado del Tratamiento
6.
Immunobiology ; 221(5): 650-6, 2016 May.
Artículo en Inglés | MEDLINE | ID: mdl-26827241

RESUMEN

Age-related macular degeneration (AMD) is the leading cause of blindness among senior citizens of developed countries, with currently unknown etiology. Despite the close associations between AMD development and inhibitory complement factor H mutations, the first step of complement activation, which is the antibody response in AMD patients, has not been studied. Here, we obtained blood and tear samples from AMD patients and Non-AMD controls. We found that compared to Non-AMD controls, AMD subjects had increased IgA titers in serum and tear, and had elevated levels of circulating antibody-secreting plasmablasts. The increase in antibody titer was limited to the IgA isotype, since no significant differences were observed in IgM and IgG isotypes between AMD patients and Non-AMD controls. Interestingly, this increased antibody response in AMD patients was correlated with disease severity, as late AMD patients had increased IgA titers in serum and tear, as well as elevated plasmablast frequency after staphylococcal enterotoxin B stimulation, compared to early AMD patients. Together, our results implicated a role of overreactive IgA responses in AMD pathogenesis.


Asunto(s)
Inmunoglobulina A/inmunología , Degeneración Macular/inmunología , Degeneración Macular/patología , Células Plasmáticas/patología , Linfocitos B/metabolismo , Linfocitos B/patología , Biomarcadores , Femenino , Humanos , Inmunoglobulina A/sangre , Inmunoglobulina G/sangre , Inmunoglobulina G/inmunología , Inmunoglobulina M/sangre , Inmunoglobulina M/inmunología , Degeneración Macular/sangre , Degeneración Macular/diagnóstico , Masculino , Persona de Mediana Edad , Células Plasmáticas/metabolismo , Índice de Severidad de la Enfermedad , Lágrimas/inmunología
7.
APMIS ; 122(9): 818-23, 2014 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-24479831

RESUMEN

Retinopathy of prematurity (ROP) is the leading cause of blindness in preterm infants. In this study, we investigated the cytokine levels in cord blood of normal preterm neonates and preterm infants developed ROP. Serum levels of 10 cytokines in umbilical cord blood were measured by multiplex protein arrays from 62 healthy preterm neonates and 30 preterm neonate cases who developed ROP at later stage. Results showed that serum levels of cytokines including interleukin 7 (IL-7), monocyte chemotactic protein-1 (MCP-1), macrophage inflammatory protein 1 alpha (MIP-1α), and macrophage inflammatory protein 1 beta (MIP-1ß) were significantly increased in cases who developed ROP than in healthy preterm neonates (3.5-fold, 3.2-fold, 3.4-fold, and 2.1-fold, respectively), whereas levels of these four cytokines did not reveal any significant differences between healthy preterm infants and normal infants. When comparing the expression of cytokines in ROP patients with different clinical parameters, ROP cases whose gestational age at delivery earlier than 29.0 weeks demonstrated increased levels of MCP-1 and MIP-1ß than those later than 29.0 weeks (p < 0.05). Also, ROP cases with birth weight less than 1.28 kg revealed significantly higher level of MIP-1ß than those who were heavier than 1.28 kg (p < 0.05). These data indicated that levels of IL-7, MCP-1, MIP-1α, and MIP-1ß were associated with increased risk of ROP, in which MIP-1ß may be further correlated with the severity of ROP.


Asunto(s)
Citocinas/sangre , Sangre Fetal/química , Recien Nacido Prematuro/sangre , Nacimiento Prematuro/sangre , Retinopatía de la Prematuridad/sangre , Estudios de Casos y Controles , Quimiocina CCL2/sangre , Quimiocina CCL3/sangre , Quimiocina CCL4/sangre , Femenino , Edad Gestacional , Humanos , Lactante , Recién Nacido , Interleucina-7/sangre , Masculino
8.
DNA Cell Biol ; 32(12): 717-21, 2013 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-24083358

RESUMEN

Age-related macular degeneration (AMD) is the leading cause of blindness in the elderly population. Evidence has shown that the human immune system may play critical roles in this disease. Inducible costimulator (ICOS) promotes T-cell activation, differentiation, and T:B-cell interactions. The aim of the study was to understand the effect of ICOS on the development of AMD from genetic polymorphism perspective and serum level perspective. Two ICOS polymorphisms, rs10183087A/C and rs10932037C/T, were tested in 223 AMD cases and 262 healthy controls. The serum level of soluble ICOS (sICOS) was compared among subjects with different genotypes, as well as between AMD patients and controls. Data showed that prevalence of rs10183087CC genotype was significantly increased in AMD than in controls (p=0.001). Function analysis revealed that subjects carrying rs10183087CC genotype had higher serum levels of sICOS than those with AA or AC genotypes (p<0.05). When we compared serum levels of sICOS between cases and controls, results showed that AMD patients had significantly increased sICOS levels than healthy donors (p<0.05). Also, wet type cases were observed to have higher sICOS levels than cases with dry type (p<0.05). These data suggested ICOS polymorphism could affect the susceptibility to AMD by elevating protein expression, and serum levels of sICOS may be closed correlated with the development and progression of this disease.


Asunto(s)
Proteína Coestimuladora de Linfocitos T Inducibles/sangre , Proteína Coestimuladora de Linfocitos T Inducibles/genética , Degeneración Macular/sangre , Degeneración Macular/genética , Polimorfismo Genético , Anciano , Estudios de Casos y Controles , Femenino , Regulación de la Expresión Génica/genética , Genotipo , Humanos , Degeneración Macular/fisiopatología , Masculino , Persona de Mediana Edad
9.
Inflammation ; 36(4): 839-44, 2013 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-23413043

RESUMEN

Proliferative vitreoretinopathy (PVR), the most common cause of failure of rhegmatogenous retinal detachment (RD) surgery, is an anomalous scarring process related to ocular inflammation. Lysyl oxidase (LOX) is a copper-dependent amine oxidase that may play important roles in ocular tissue integrity. The aim of this study was to investigate whether polymorphisms in the LOX gene were associated with susceptibility to RD and PVR. We screened the promoter region of LOX gene and tested two previously reported polymorphisms (-22 G/C and 473 G/A) in RD patients with or without PVR and healthy controls. Data showed that prevalence of the -22CC genotype and -22C allele were significantly higher in the RD cases than in the control group after adjustment for sex and age (p < 0.001 and p < 0.001, respectively). Similarly, a significant difference was observed regarding LOX 473GA genotype and 473A allele between RD patients and healthy donors after adjustment for sex and age (p = 0.005 and p = 0.012, respectively). Also, when compared to RD cases without PVR, patients who developed PVR had significantly higher numbers of -22CC genotype and -22C allele (p = 0.048 and p = 0.003, respectively). These results indicated that LOX polymorphisms were associated with increased susceptibility to RD and PVR and suggest a potential correlation between LOX and ocular inflammation.


Asunto(s)
Enfermedades Hereditarias del Ojo/genética , Predisposición Genética a la Enfermedad , Proteína-Lisina 6-Oxidasa/genética , Desprendimiento de Retina/genética , Vitreorretinopatía Proliferativa/genética , Secuencia de Bases , Estudios de Casos y Controles , Enfermedades Hereditarias del Ojo/cirugía , Femenino , Estudios de Asociación Genética , Variación Genética , Genotipo , Humanos , Masculino , Persona de Mediana Edad , Polimorfismo de Nucleótido Simple , Regiones Promotoras Genéticas , Desprendimiento de Retina/cirugía , Análisis de Secuencia de ADN
10.
Biochem Biophys Res Commun ; 420(3): 600-4, 2012 Apr 13.
Artículo en Inglés | MEDLINE | ID: mdl-22445756

RESUMEN

Copper is an indispensable metal for life. For convenience of genetic manipulation and sharing similar metabolic pathway of metals with mammalian cells, the yeast Saccharomyces cerevisiae is widely used for metal homeostasis studies. Storage and mobilization of copper ions in yeast vacuoles or mammalian lysosomes are important for cells to avoid their toxicity and elevate their utility. Though regulation of other genes involved in copper homeostasis is well understood, the regulation of gene encoding low-affinity copper transporter Ctr2p, which mediates mobilization of vacuolar or lysosomal stored copper ions, is still unclear. In this study, we found that copper depletion can upregulate yeast CTR2 gene transcription while copper overload downregulate it. The copper-depletion induced CTR2 transcription can be abrogated by genetic deletion of copper-sensing transcription factor Mac1p. Though absent of consensus Mac1p binding sequences, CTR2 promoter region is demonstrated to be occupied by Mac1p, according to our results of chromatin immunoprecipitation (ChIP) assay. Overexpression of Mac1p can upregulate CTR2 transcription and partially complement the growth defect of copper-deficient yeast strain. Taken together, our results suggest that Mac1p can activate the expression of vacuolar copper transporter Ctr2p in response to copper deficiency, resulting in yeast resistance to copper starvation.


Asunto(s)
Proteínas de Transporte de Catión/genética , Cobre/metabolismo , Regulación Fúngica de la Expresión Génica , Proteínas Nucleares/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/genética , Factores de Transcripción/metabolismo , Proteínas Nucleares/genética , Regiones Promotoras Genéticas , ARN Mensajero/biosíntesis , ARN Mensajero/genética , Proteínas SLC31 , Saccharomyces cerevisiae/metabolismo , Factores de Transcripción/genética , Regulación hacia Arriba
11.
Int J Ophthalmol ; 4(1): 44-8, 2011.
Artículo en Inglés | MEDLINE | ID: mdl-22553607

RESUMEN

AIM: To investigate the therapeutic effects of local and systemic administration of AMD3100 for alkali burn induced corneal neovascularization (CNV) in mice. METHODS: CNV was induced in vivo by alkaline burn of cornea in C57BL/6 mice. AMD3100 was administrated topically by subconjunctival injection or systemically by intraperitoneal injection for 7 days; balanced salt solution was administrated topically or systemically as a control respectively. Inflammatory index was evaluated by slit-lamp biomicroscopy and inflammatory cells infiltrated to cornea tissue were detected by histologic analysis at multiple time points. CNV was compared between the local and systemic treated mice 2 weeks after alkali burn, as quantified by CD34 immunostaining. Fluorescence-Activated Cell Sorter Analysis was used to investigate the mobilizing effects of EPC in mice after subconjunctival injected or intraperitoneal injected AMD3100. Immunohistochemistry was used to detect the expression of endothelial progenitor cells (EPC) marker proteins VEGFR2 and CD34. RESULTS: Three days after alkali burn, infiltration of inflammatory cells was found in corneal tissue. At the first 7 days of local injection group, the number of inflammatory cells was significantly lower than that in systemic injection group. CNV could be seen at the 7(th) day, and at the 14(th) day reached the peak, then started to decrease. The number of CNV in the subconjunctival injection group was 7.57±1.26 per 0.034mm(2), compared to a number of 14.87±2.21 per 0.034mm(2) in the control group (P<0.05). On the contrary, the number of CNV in the intraperitoneal injection group was a little higher than that in the control group, 16.34±1.53 per 0.034mm(2)vs 13.26±1.87 per 0.034mm(2). The research also showed that intraperitoneally, but not subconjunctivally injected AMD3100 could mobilize EPC. On the other hand, subconjunctival, but not intraperitoneally injected AMD3100 could reduce the expression of EPC marker proteins. CONCLUSION: In mice locally administrated AMD3100 can reduce the number of alkali burn induced CNV. The number of inflammatory cells and inflammatory responses in corneal tissue.

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